A cardiologist answers your questions about myocarditis and COVID-19

UC Davis Health Cardiologist Nayereh Pezeshkian discusses COVID-19, its impact on the heart, and the rare risk of developing heart complications after a COVID-19 vaccine. 

How does COVID-19 affect a person's heart?

About 20-30% of patients hospitalized with COVID-19 show heart problems. These patients tend to have more severe symptoms and worse health outcomes. Their heart issues can be due to direct damage from the virus, resulting in heart inflammation, or the indirect effect of inflammatory proteins (known as cytokines) released in the bloodstream. Heart muscle inflammation (myocarditis) commonly manifests as heart failure or through uneven heartbeat (arrhythmia). Sudden death in COVID-19 patients caused by arrhythmia can be a consequence of these heart problems.

COVID-19 is also associated with the inflammation of the vascular lining and an increased risk for blood clots forming in large blood vessels and small vessels, particularly in the heart and lungs. The inflammation and the blood clots can lead to poor oxygen levels in these critical organs.

The risk of heart attack and stroke is also higher among COVID-19 patients.

With COVID-19, the right side of the heart must often work harder to pump blood to inflamed lungs filled with fluid and vessels filled with blood clots. This extra effort will put additional strain on the heart, causing right heart enlargement. This disease can show up as leg swelling and liver and kidney failure.

What do we know now about the long-term impacts of COVID on the cardiovascular health of patients?

Most cases of myocarditis heal if the patient survives the acute illness. However, in some patients, cell death and scar formation due to myocarditis, heart attacks, or damage to the vascular lining may result in long term problems, such as heart failure and rhythm abnormalities.

Are heart disease patients still at a higher risk of developing severe COVID-19 symptoms? Does the vaccine help prevent that?

Elderly patients and those with heart and vascular disease are at higher risk of severe covid-19 and even death. High-risk patients include those with the following conditions:

• Heart failure
• Coronary artery disease (CAD)
• Heart muscle disease (cardiomyopathy)
• Obesity
• High blood pressure
• Diabetes

These preexisting conditions, such as obesity and diabetes, intensify the role of the virus in causing inflammation and forming clots. In addition, patients with already strained hearts and lungs have more difficulty with COVID-related complications, such as low oxygen, low blood pressure, heart inflammation and blood clots. These complications can easily become severe and turn deadly.

The high-risk groups of elderly patients and those with cardiovascular risk factors accounted for the large majority of COVID-related deaths early on, and that’s why their vaccination was prioritized.

For people with these conditions, the vaccine is even more critical and can help to lower the risk of hospitalization and death. Vaccination markedly reduced hospital admission and death rate by 90% among vaccinated individuals.

People are concerned about heart inflammation linked to the vaccine. What can you tell them?

Rare heart inflammation cases (around one in 6000) were reported in teenagers after their COVID-19 vaccination. These cases have been mild and self-resolving. However, the chance of developing severe illness and death after a COVID-19 infection is much higher (2-10%). There is a higher risk of myocarditis from COVID itself than there is from the vaccine.

At this time, most hospitalization - particularly to critical care - and deaths are related to unvaccinated groups. So, I tell my patients to get vaccinated.

What do you advise your patients do to maintain their heart health?

Eat well, stay active, and get vaccinated!